Kicking a football requires less force than kicking a basketball. Why?

Give an example of a force that merely changes the direction of motion of a body.

$(a)$ $(i)$ Define momentum. State its $SI$ unit.
$(ii)$ An object of mass $50 \ kg$ is accelerated uniformly from a velocity of $4 \ m/s$ to $8 \ m/s$ in $8 \ s$. Find the magnitude of the force exerted on the object.
$(b)$ State Newton's first law of motion.

$(i)$ Define momentum. Write its $SI$ unit.
$(ii)$ How much momentum will an object of mass $10 \ kg$ transfer to the floor if it falls from a height of $5 \ m$? $(g = 10 \ m \ s^{-2})$
$(iii)$ Explain how a karate player can break a pile of tiles with a single blow of his hand.

Give two examples in each case,of a force that:
$(i)$ lifts
$(ii)$ pushes
$(iii)$ pulls
$(iv)$ stretches
$(v)$ compresses
$(vi)$ resists
$(vii)$ attracts
$(viii)$ squeezes

$(a)$ When a motorcar makes a sharp turn at a high speed,we tend to get thrown to one side. Why?
$(b)$ State Newton's first and third law of motion.
$(c)$ $A$ force of $5 \ N$ gives a body of mass $m$ an acceleration of $10 \ m \ s^{-2}$. Calculate the mass of the body in grams.